Combined fire and burglar alarm

ABSTRACT

A self-powered combined burglar and fire alarm is provided employing a plurality of self-powered photoflash transmitter units that are selectively triggered into operation by burglar activity or by fire to produce a high intensity pulse of light. A centralized detector responds to the light pulse produced by anyone of these triggered units to annunciate the fire or the presence of the intruder.

United StatesPatent [1 1 Litman et al.

4] COMBINEDIFIRE AND BURGLAR ALARM I [76] Inventors: Alan L. Litman,Hartwood Dr.,

Pittsburgh, Pa.; Norman C. Eisenstat, 716 Linden Ave., Pittsburgh, Pa.15208; Don R. Horowitz, 5464 Darlington Rd., Pittsburgh, Pa. 15219 22Filed: May 11, 1972 21 Appl. No.: 252,224

[52] US. Cl 340/219, 340/227.1, 340/303, 340/416 [51] Int. Cl. G08b19/00 [58] Field ofSearch 340/219, 303, 227, 227.], 340/420, 416;116/87, 107

[56] References Cited UNITED STATES PATENTS 3,699,569 10/1972 Lee..340/227.1

[ Apr. 16, 1974 3,095,556 6/1963 Fuller 340/227.1 2,196,961 4/1940Epstein 116/87' 1,838,144 12/1931 l-lolmes.... 340/227.1

11/1946 Padilla 340/227.[

Primary E.\'aminer John W. Caldwell Assistant Examiner-Marshall M.Curtis Attorney, Agent, or Firm-Paris, Haskell & Levine ABSTRACT A.self-powered combined-burglar and fire alarm is provided employing aplurality of self-powered photoflash transmitter units that areselectively triggered into operation by burglar activity or by fire toproduce a high intensity pulse of light. A centralized detector respondsto the light pulse produced by anyone of these triggered units toannunciate the fire or the presence of the intruder. I

7 Claims, 4 Drawing Figures moses-F FIG.1

FIG. 3

26 l? ALAR LIGHT LIGHT FLASH A FIG. u

LIGHT FLASH PHOTO CELL FLASH 1 COMBINED FIRE AND BURGLAR ALARM STATEMENTOF THE INVENTION This invention relates to combined burglar and firealarm systems that are useful for inexpensively guarding the interior ofbuildings against unauthorized intrusion by burglars, as well as warningof the existance of fire.

RELATED APPLICATIONS In an earlier application of Alan L. Litman, Ser.No. 137,275, filed Apr. 26, 1971, now Pat. No. 3,714,647 there isprovided a burglar alarm system employing individual photoflash lightpulse transmitter units that are triggered by the unauthorized openingof a door or window to emit a high intensity light pulse. A plurality ofsuch transmitters guard all doors and windows of the building; and incombination with a centralized light pulse detector and receiver,function to annunciate the presence of a burglar entering through any ofsuch openings. In a preferred system, each such transmitter employs adisposable and inexpensive contact actuated pyrotechnic photoflash unitthat is self-energizable and does not require an electrical battery orother power source. A complete burglar alarm system may therefore beprovided employing a minimum of electrical wire and considerably lessinstallation costs than alternate alarm systems.

SUMMARY OF THE INVENTION AND ADVANTAGES According to the presentinvention, there is provided a similar system employing a plurality ofindividual transmitter light pulse units but with each such unitincorporating an additional sensor that responds to fire or heat totrigger the unit. Thus each such transmitter responds to either theunauthorized entry or attempted entry by a burglar or, alternatively,responds to fire or heat to emit its high intensity light pulse. As inthe earlier application, this light pulse is transmitted to acentralized light detector and receiver which is, in turn, coupled tooperate suitable visual or audible signaling means at a police or firestation, or located elsewhere as might be desired.

Since it is customary in the construction of many buildings to providedispersed doors and windows at opposite ends and at the sides, thecorresponding network of transmitters spaced at all of said openings forburglar protection provides a rather. comprehensive dispersion ofsensors for fire warning purposes also. Addition transmitter units may,of course, be used at locations where a window or door opening does notexist to provide fire protection alone at such locations.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic illustration of alight pulse transmitter unit interconnected to a window,

FIG. 2 is an enlarged sectional view illustrating de- I tails of apreferred transmitter unit, and

DESCRIPTION OF A PREFERRED EMBODIMENT As illustrated in FIGS. 1 and 2the photo flash transmitter 10 is preferably a small, inexpensive,disposable unit that may be easily attached to a window frame 12' ordoor frame and easily connected by a short chain or cable 11 to theopenable window 13, door or other access opening member. Any number ofsuch units may be employed in a room or building since each unit iscompletely independent in operation from the others.

A preferred transmitter unit 10 as shown in FIG. 2 employs a two pieceopenable hollow molded plastic housing having a pivotable forward wallordoor 14 and containing one or more single use, disposable photoflashbulbs 15 supported inside. The bulbs 15 are arranged to be triggeredupon opening of the door 14 to transmit a high intensity light pulseradiated outwardly through the open door 14 and over a wide angle.

According to the invention, it is desired to employ highly reliable,inexpensive, and self-powered photoflash units having a relatively longshelf life. A multiple light flash unit of this type is presently soldby Sylvania Electric under the name MAGICUBE, having an advertisedreliability of operation of 99.7 percent. This multiple unit includesfour minatureflash lamps 15A, 15B, etc., interconnected in a box likeconfiguration supported on a base 16. Each different flash unit isindividually triggerable by displacing aseparate driving pin such as17A. These units 15 emit light by combustion of zirconium inside of eachbulb, and this combustion is initiated by a pyrotechnic impact ignitorincorporated within the unit for each bulb and actuated by minordisplacement of the pin, such as 17A. No seperate electrical battery orother source of power is required. Each such flash element produces anillumination of approximately 2000 beam candle power seconds, with mostof the energy being generated in a transient peaked pulse, of about 10milliseconds in time duration.

In the preferred embodiment of FIG. 2, a. pair of such flash bulb units15A and 15B are triggered simultaneously in response to either a burglarentering the .door or window or alternatively in the event of fire orheat. This operation is as follows:

The pivotable door 14 of the housing 10 is mounted for rotation on shaft18A and is normally urged by a compressed spring to rotate or pivot in aclockwise direction in FIG. 2. Upon opening of this door, a lowerportion of the door 18, or an extension thereof, moves upwardly andstrikes both of the downwardly projecting pins 17A and 17B, therebyigniting both of the light flash units 15A and 15B together. Thecombined light pulses from both bulbs is radiated outwardly through theopen door in the housing.

The door 14 is normally maintained in the closed position shown by thepresence of a heat fusible plug 20 of conical shape, as shown. This plug20 is inserted into an opening provided in the base of the transmitterhousing 10 and is accommodated as a door stop between the lower end 18of the pivotable door 14 and a fixed projecting portion 21 extendinginside of the housing, as shown. This fusible plug 20 also supports thepull chain 11.

It is believed now apparent that upon removal of the fusible plug 20, byeither pulling downwardly on the chain 11 or by melting of the fusibleplug 20 in response to heat, the door 14 is released; and under theforce of the compressed spring 19, opens to trigger the flash lightbulbs as discussed above.

As discussed in said earlier patent application of Alan L. Litman, aseries of such transmitter units are located and installed at variousdoors and windows to provide complete protection of a building againstthe entry or attempted entry'of unauthorized persons. According to thepresent invention still additional transmitters may also be installed atlocations where no doors or windows exist to provide fire protectionalone at such locations.

All of these transmitters are preferably self-powered and require noelectrical wiring or other external power source.

In optical communication with each transmitter, or group oftransmitters, is a centralized receiver alarm circuit as schematicallyillustrated in FIG. 3. This receiver includes a light sensitive membersuch as a photocell 25, an amplifier switching circuit 26, and an alarm27. The receiver responds to the generation of a transient light pulsefrom any one of the photoflash transmitters to energize the audible orvisible signal alarm 27, warning of an unauthorized violation of theintegrity of the guarded premises or of the existance of heat or fire atany of the transmitter locations. The amplifier switching circuits 26 inthe receiver contains circuitry rendering the receiver insensitive toambient lighting conditions, such as sunlight, or to changes in suchambient conditions, and preferred circuitry for this purpose isdisclosed in said earlier Litman application.

If it is desired to completely eliminate dependence upon externalelectrical power wiring,'the centralized receiver may be powered bybattery or by other selfcontained source. Alternatively, it may bedesigned to use conventional AC electrical power, or DC power as isavailable in certain countries.

Where the premises to be protected are comprised of a series ofpartitioned areas, such as separated rooms, a receiver of this type maybe located in each such room. Alternatively, a series of light pulseproducing relays may be employed to optically interconnect the differentpartitioned locations together in a concatenated light pulse chain usingonly one or more centralized alarms or warning systems. A light pulseproducing relay circuit of this type is schematically shown in FIG. 4,and specific circuitry is shown in the earlier Litman application. Sucha device is similar to the alarm circuit of FIG. 3, but instead ofhaving the receiver energize an alarm 27, the responding amplifiersignal is employed to electrically energize a flashbulb socket and bulb29. In operation, a series of such light relays are located in opticalcommunications with one another from room-to-room, and with various'ofthese relays in position to observe the transmitters. A light pulseproduced by any one of the transmitters anywhere in the optical chain,is propagated to its related light relay. This relay thereupon producesa sympathetic light pulse that is radiated to the next relay, and soforth down the chain, until an alarm operating receiver is energized. Byproper placement of such light relays, all locations of a building, onall floors may be placed in optical communication with one another.

The transmitter units may also be electrically or mechanically connectedwith other types of sensors; or other alarm systems may be coupled intothe optical system. For example, foot or pressure operated sensorswitches may be connected to energize the receivers or light pulseproducing relays. Similarly smoke detectors or pressure detectors mayalso be coupled into the sys tern.

The signal alarm circuits may be of visual or audible types, or may becoupled by telephone wires, or radio beams to provide a warning signalat a location remote from the optical system. i

As also discussed in said earlier application, the light flashing unitsare preferably inexpensive, single use, expendable, self-powered devicesthat must be replaced after being triggered. However, multiplephotoflashing units may be employed. For a secrecy system, infra-red,ultra-violet, or other filters may be used over the transmitters, topermit only light wavelengths to be transmitted that are not visible tothe burglar yet detectable by properly designed receivers.

The fusible plug 20 is preferably molded in a shape and of low meltingpoint metal alloys as to partially melt and break apart at temperatureclose to 136 degrees F. A preferred construction that reliably providesthe desired break apart action comprises molding the member with acentral hub and two radial spokes 30 and a discontinuous outerperiphery.

Many other changes and variations may be made by those skilled in thisart and this invention should ac cordingly be limited only by thefollowing claims:

We claim:

1. In a combined burglar and fire alarm system,

a light pulse generator including,

operating means for causing said generator to emit a light pulse,

means coupled to said operating means and responsive to movement toactuate said operating means, and

means coupled to said operating means and responsive to the presence ofheat to actuate said operating means,

and a light pulse detector spaced from and in optical communication withsaid generator to produce an alarm upon detection of said light pulse.

2. In the system of claim 1', a plurality of such generators spacedapart from one another and all in optical communication with saiddetector.

3. In the system of claim 1, each of said generators including aphotoflash unit, said operating means including a springdn'ven memberfor triggering said photoflash unit and said heat responsive meansincluding a heat fusible element.

4. In the system of claim 3, said photoflash units being self-poweredand contact operated to ignite a pyrotechnic flash material.

5. In the system of claim 1, additional means for sensing otherconditions and coupled to said system.

6. In the system of claim 1, said generator operating means including aspring biased triggering member, said heat responsive means including aheat fusible element positioned as a stop to prevent spring actuatedmovement of said triggering member, and said means responsive tomovement interconnecting said fusible element for removal from said stopposition in response to movement of the member to be protected, wherebysaid triggering member is selectively released in response to sufficientheat applied to the fusible element and in response to movement of themember to be prospring biased triggering member.

1. In a combined burglar and fire alarm system, a light pulse generatorincluding, operating means for causing said generator to emit a lightpulse, means coupled to said operating means and responsive to movementto actuate said operating means, and means coupled to said operatingmeans and responsive to the presence of heat to actuate said operatingmeans, and a light pulse detector spaced from and in opticalcommunication with said generator to produce an alarm upon detection ofsaid light pulse.
 2. In the system of claim 1, a plurality of suchgenerators spaced apart from one another and all in opticalcommunication with said detector.
 3. In the system of claim 1, each ofsaid generators including a photoflash unit, said operating meansincluding a spring driven member for triggering said photoflash unit andsaid heat responsive means including a heat fusible element.
 4. In thesystem of claim 3, said photoflash units being self-powered and contactoperated to ignite a pyrotechnic flash material.
 5. In the system ofclaim 1, additional means for sensing other conditions and coupled tosaid system.
 6. In the system of claim 1, said generator operating meansincluding a spring biased triggering member, said heat responsive meansincluding a heat fusible element positioned as a stop to prevent springactuated movement of said triggering member, and said means responsiveto movement interconnecting said fusible element for removal from saidstop position in response to movement of the member to be protected,whereby said triggering member is selectively released in response tosufficient heat applied to the fusible element and in response tomovement of the member to be protected.
 7. In the system of claim 6,said light pulse generator comprising a self-powered mechanical contactactuated photoflash unit operated upon contact by said spring biasedtriggering member.